Correspondence with B.E.J. Pagel and D.R. Palmer, Royal Greenwich Observatory, regarding mechanical and thermal stability in the design of the Anglo-Australian Telescope Cassegrain spectrograph, with a reference to a recent Joint Policy Committee meeting in Canberra, during which opinions contained in V.C. Reddish's memorandum on guiding and acquisition of 10 March were attributed to Redman erroneously, especially the 'impossible suggestion' that the spectrograph slit width could be servoed.